DIGITAL AUDIO OUT and ARC Output 5.1 Channel Audio Even When I Watch a Netflix Program with 2 Channel Audio

If Digital audio out in the Sound menu of your TV is set to Auto1, the DIGITAL AUDIO OUT (OPTICAL) and HDMI ARC ports output 5.1 channel audio even if the Netflix program you're watching has 2 channel audio. This is a TV specification and part of the normal operation.